Dátum: 2000. december 11., 23:31
Feladó: Külső hozzászóló --
Tárgy: ujabb fekete lyuk-jelolt
T. Csillasok,
Az elobb jott a kovetkezo erdekes hir, amit az IAU Circular szamara
adtak le a szerzok:
>
XTE J1118+480
J. McClintock, M. Garcia, P. Zhao, N. Caldwell, and E. Falco,
Harvard-Smithsonian Center for Astrophysics, report: "Spectroscopic
observations of this X-ray nova with the new 6.5-m MMT on Dec. 1 & 4
show that it contains a black hole primary of at least 6 solar masses.
...
the spectra
contain both broad Balmer emission lines and the numerous absorption
features characteristic of a late-type dwarf. Robust velocity
measurements were obtained by cross-correlating the individual spectra
(range 490-650 nm) against the spectra of several bright dwarfs
(K5-M2). The eight velocities provide good phase coverage and yield a
velocity amplitude of K = 709 +/- 11 km/s and an orbital period of P
0.1700 +/- 0.0003 days (IAUC 7412,7418). The large value of the mass
function, f(M) = 6.3 +/- 0.3 solar masses, is rivaled only by that of
V404 Cyg.
>
Azaz a korabban 3+ meteres Multiple Mirror Telescope jol uzemel az
1 db 6.5 m-es fotukrevel, amivel a fenti ocsmany nevu
rontgen-novat spektroszkopizaltak. A szinkepvonalak
periodikus eltolodasabol kijott, hogy a masodkomponens
kb. 700 km/s-os keringesi sebesseggel teker alig 4 oras
periodussal a rontgen-tartomanybeli felfenyesedesert
felelos fokomponens korul. Mindebbol a "lathatatlan"
tars legalabb 6.3 naptomeg, azaz mar nem csillag, hanem fekete
lyuk, amit csak a hasonlo jellegu V404 Cyg mul felul.
Nos, meglehetosen sotet dolgok tortennek az XTE J1118+480
kornyeken...
Kiss Laszlo
variabilista